1. Field of the Invention
This invention relates to a process for reclaiming scrap vulcanized rubber by using a novel reclaiming agent.
2. Description of the Prior Art
As a result of recent remarkable development of motorization, amount of scrap tires has increased rapidly and its treatment has become a big problem. Heretofore, scrap tires have been used for filling-up, the structural shape itself has been used or they have been simply burned. However, these treatments are not desirable from viewpoint of prevention of environmental pollution and effective use of material sources.
On the contrary, there have been studies processes for devulcanizing scrap vulcanized rubber to produce reclaimed rubber and processes for recovering oils or carbon black by thermal decomposition of scrap vulcanized rubber with chemicals.
Heretofore there have been proposed various reclaiming methods for scrap vulcanized rubber, but most of them need a high temperature over 150.degree. C., and therefore such methods can be carried out only where a particular apparatus therefor is available.
Further, most of the conventional reclaiming methods were developed for natural rubber and could not effectively reclaim rubbers containing a large portion of synthetic rubber.
As a reclaiming agent, dixylyl disulfide is known (cf. Encyclopedia Polymer Science Technology, 1970, Vol. 12, pp. 341-355). This reclaiming method using dixylyl disulfide is known as oil pan method which comprises treating scrap vulcanized rubber in an autoclave at 190.degree.-200.degree. C. for 4-5 hours, but physical properties of the rubber thus reclaimed are not so good.